Yesterday I finished Skyward sword, so here is a little opinion of mine. If you haven't finished it yet: There are a few spoilers ahead!!
Overall I think it's a fun Zelda, but definitely not among the best! The graphics are a mixed bag. Sometimes beautiful, some times bad. Nintendo tried a cross between Windwaker style and Twilight princess style, but in my opinion both are better then Skyward sword style. The music is also mixed. Some tracks are awesome and some are a bit less. As for swordplay: It is fun and it works. But it didn't blew me away as much as the touchscreen controls in Phantom hourglass and Spirit tracks. Though in both instances I would not cry if they went back to button controls. I don't have trouble with the schemes Nintendo came up with so far. The first bunch of bokoblins and the first Ghirahim battle gave me lots of trouble though.
As for the structure of the game: There are only 3 different areas and sadly they aren't linked. However, they are pretty big. Especially Lanayru desert was big and probably the best part of the game, with the cool robots, prehistoric snails/prawns and all the timeshift stone stuff. However, there is not really a single dungeon that really stands out. Lanayru mining facility is probably the best, though it has not the magnitude of lets say City in the sky from Twilight princess. The most dissapointing dungeon probably is Ancient cistern. It looks awesome and you hope for a very big and complex dungeon. But when you have discovered you have to flip certain lily leafs to get further, the whole level is pretty short and easy. And the whip isn't that great either since you can't hit enemies with it like in Spirit tracks. The boss was pretty fun though. Overall the game's puzzles are very easy. Only in the pirate hideout and in the last level there was a instance where I had to think for a few minutes to find the solution. But for the rest it was smooth sailing. Spirit tracks had much harder puzzles.
The best item probably was the gust bellows. And the beetle was pretty fun too. The silent realms where a lot better then the boring Wolf-parts from Twilight princess, because they where shorter and I think also in a smaller space. It wasn't that bad. I also loved the Kikwi's and the Mogma's. And the flying was fun too. The biggest dissapointment though was The sky. This could easily have been the sea from Windwaker in scope. But sadly it's just a very small hub with almost nothing to do. And it's only around the 50 hour mark that you learn your true objective.
It isn't a small game though! It took me 75 hours and I have still not found everything. While I am not a big fan of Ghirahim (though I loved the scary ritual he pulled on Zelda), his fights where probably the hardest and most fun. The first battle looked boring to me on the internet, but when I finally played it I had to admit it was great! Never before did a first boss give me so much trouble! And he did look during the last battle! As for Fi: Awesome design but bad voice. I hate autotune!
So what should Nintendo do next? Going back to the Windwaker style (I guess they can improve it a lot on the Wii u), or using the awesome realistic style they showed in the Wii u demo, or coming up with a totally new style. As for Skyward sword style: I only want to see it again if they can REALLY improve it! And I also want Young Link back. What's wrong with young Link in a homeconsole Zelda nowadays? I would love to see Retro studios or Nintendo's Tokyo studio on the game. But if they decide not to, then at least get the puzzle-makers from Spirit tracks to come up with awesome puzzles again but this time in a 3D eviroment! But the next homeconsole Zelda is far of. First we get a 3DS Zelda. I am sure about that. It will have 3D. The rest is a guess. But the last 2 handheld Zelda's where great (especially Spirit tracks), so I look forward to it!
So overall it was a mixed Zelda, but I had certainly fun. Let's see what they do with the next Zelda!

I loved the bosses in Twilight Princess, they were amazing, but they were also a fair bit too easy... the dungeons were also really good and actually quite expansive. Skyward Sword's dungeons and bosses just seem really small and short...